"The waking-up process has begun and will take until Tuesday," a source told the newspaper. "There is real concern that the part of the brain that controls motor skills may have been compromised, leaving her as either a vegetable or in a wheelchair."

The insider also added that the comedian's family is considering a possible lawsuit against Yorkville Endoscopy, where Rivers, 81, had been undergoing a procedure on her throat when she stopped breathing on Thursday. Rivers was then rushed to Mount Sinai hospital where she was reportedly put on life support.

Rivers' family is staying optimistic. "We are keeping our fingers crossed," her daughter Melissa said in a statement on Sunday.